In Anton syndrome, cortical blindness occurs, but patients do not notice it. The brain continues to produce images that affected individuals accept as images of the environment and thus fail to see their blindness. Patients often do not consent to treatment because of their lack of insight.
What is Anton syndrome?
Anton syndrome is characterized by cortical blindness, making it a neurological syndrome. Thus, in the context of the syndrome, blindness is not caused by damage to the eyes but is related to a lesion of the cerebral cortex. In Anton’s syndrome, the visual pathways in both hemispheres of the brain are damaged, so that visual stimuli no longer reach the brain and can likewise no longer be processed there. Those affected also suffer from anosognosia and do not recognize the diagnosis of their own blindness. In Anton’s syndrome, anosognosia is also caused by damage to certain areas of the brain. The syndrome is named after the Austrian neurologist Gabriel Anton, who first described the clinical picture in the 19th century. At the time, he described the case of a lady who does not recognize her blindness and actually seeks medical advice because of a word-finding disorder.
Causes
Anton’s syndrome is usually the result of a stroke. Typically, the causative cerebral infarction affects the visual cortex of both cerebral hemispheres. The visual cortex is supplied with arterial blood by the brainstem artery. Both posterior cerebral arteries arise from this artery. A circulatory disturbance in these arteries affects the visual cortex and, according to current research, probably triggers a connectivity defect in the processing of visual information. That is, in Anton’s syndrome, the eyes actually see, but the conscious mind no longer gains insight into the visual stimuli. For example, the visual cortex no longer relays visual information to the brain center for language. Anosognosia results in the center for verbalizing visual information simply making things up because of the missing information. In addition to stroke, Anton syndrome can be caused by a lesion of the anterior visual pathways, hemorrhage, or epilepsy.
Symptoms, complaints, and signs
Anton syndrome is characterized by what is usually complete blindness of cortical origin. The lack of insight for the lack of vision is the most characteristic symptom of the syndrome. Affected individuals do not tell themselves they can see, but actually have no doubt about it. Their own brain deceives them by providing them with images that are consistently fabricated. Most often, Anton syndrome patients run into door frames, walls, or even in front of cars because of these fictitious, but for them absolutely real, images. They trip, stagger and stumble. They no longer recognize objects and people. They give themselves and others numerous explanations for this. Thus they see their own clumsiness in stumbling and stumbling. They usually blame the non-recognition of objects and people on bad light or lack of attention. They do not intentionally deceive other people or even themselves about their blindness, but are actually unaware of their blindness.
Diagnosis and course
The physician makes the diagnosis of Anton’s syndrome by taking a medical history, imaging the brain, and vision tests. Specifically, in the history, patients deny being asked if their vision has decreased recently. In the vision tests, they describe objects, numbers, and letters vividly but completely incorrectly. Imaging eventually reveals lesions of the visual cortex. Whether a stroke or damage to the anterior visual pathway has triggered Anton’s syndrome can be determined either by imaging alone or with the help of various tests on the cerebral arteries. Because Anton’s syndrome patients do not show insight, the prognosis for this condition is rather unfavorable. If left untreated, neurological deterioration of the syndrome may develop. Rejection of diagnostic methods sometimes even prevents the diagnosis from being confirmed. Rehabilitation measures can achieve healing success, especially in cases of damage caused by epilepsy, if the patient consents to treatment.
Complications
Anton’s syndrome results in severe psychological and physical complications.On the one hand, it can be a blindness in the patient, which, however, is not seen because the brain continues to produce images of the environment. Anton’s syndrome leads to a considerable restriction of everyday life and quality of life. Also the treatment proves to be difficult, because the affected person does not realize directly that he is ill with Anton’s syndrome. By imagining that he can continue to see, the patient poses a danger to himself and to other people. Thus, it often happens that the affected person runs against objects or even in front of vehicles. This can lead to accidents, which in the worst case can be fatal. Therefore, the affected person with Anton’s syndrome is in any case dependent on the help of other people, as long as no treatment has occurred. The syndrome itself can be easily identified with an eye test. Treatment usually involves discussions with a psychologist. However, it may take a long time for the admission to Anton syndrome to occur in the patient. After that, various measures can be taken to increase the patient’s orientation and mobility. Life expectancy is reduced in the respect that the patient is at increased risk of being involved in accidents.
When should you see a doctor?
Anton syndrome should be evaluated by a medical professional as soon as possible. The most effective treatment, neuroplasticity, is effective only for the first twelve weeks after blindness. After that, much less effective physical and occupational therapy measures must be taken. Since those affected usually do not realize their blindness themselves, diagnosis usually occurs too late and treatment options are correspondingly limited. Therefore, in the best case, preventive measures are taken. It is recommended to consult a doctor already at the first circulatory disturbances or other health problems that could lead to a stroke and subsequently to Anton’s syndrome. Patients with epilepsy or a lesion of the anterior visual pathways should inform themselves in time about possible sequelae. If Anton’s syndrome then occurs, the condition can be more easily accepted. Anyone who suspects that another person suffers from the rare syndrome should accompany him or her to a doctor and clarify the causes. Other contacts include ophthalmologists as well as neurologists and angiologists.
Treatment and therapy
Treatment of Anton’s syndrome is challenging because patients are absolutely unclear about their own disease. Therapeutic steps are usually vehemently rejected and considered futile. The necessary therapy is symptomatic and interdisciplinary. Neurology plays just as important a role in the therapeutic path as psychiatry, internists and physiotherapists. Above all, the causal underlying disease must be recognized and consistently treated. In psychotherapeutic and psychopharmacological therapy, patients are convinced of their blindness through consistent reminders, although this is often fraught with conflict potential. In physical and occupational therapy, deficits relevant to everyday life are remedied as far as possible. Compensation strategies are learned and can serve to compensate for the deficits. Neuroplasticity is a rather newer therapy option for cortical blindness, which can reactivate visual perception via stimulation of adjacent cortex neurons. However, because the method shows success only 12 weeks after blindness, and Anton syndrome patients usually do not even see the doctor during this short period because of their lack of insight, the procedure is often not considered for Anton syndrome.
Prospect and prognosis
In Anton syndrome, a prognosis is largely dependent on the patient’s insight into the disease and his or her cooperation in the treatment process. In almost all cases, insight is not present in sufferers. Therefore, the implementation of treatment is difficult or impossible. Without medical care, the symptoms remain permanently. There is no worsening, but also no improvement of the state of health. With treatment, symptoms can be relieved. Proven neuroplastic techniques result in relief within weeks and months. In addition, intensive psychotherapy works on the patient’s cognitive patterns, faulty beliefs and behavioral changes.This procedure is extremely difficult and often takes several months or years. However, due to the lack of insight into the disease, the few patients who have declared their willingness to undergo treatment break off the therapy prematurely. In addition, the lack of insight means that there is a high potential for conflict between the patient and the treating physicians and therapists. The adversity complicates the outlook and only in extremely rare cases is there significant progress in the healing process or a complete cure. On the other hand, if there is acceptance of the disease or trust in the treating physicians, there is a good prognosis.
Prevention
Anton’s syndrome can be prevented in moderation via the same steps as stroke, which usually triggers the syndrome.
Follow-up
Anton syndrome is a chronic condition that cannot be treated causally. Follow-up care focuses primarily on regular screenings and adjusting treatment as constantly as possible to the current health status of the affected person. In addition, measures must be taken to prevent the health condition from worsening. These include therapeutic exercises on the one hand and comprehensive medication on the other, which must also be regularly checked and adjusted. The patient must be examined by a doctor once a week. In the later stages of the disease, inpatient treatment in a hospital is required. Part of the follow-up care are eye tests and neurological examinations, which depend on the severity of Anton’s syndrome. If accompanying symptoms occur, additional physicians must be consulted. Psychological counseling may also be necessary. Not only the affected persons themselves, but also the relatives and friends often need the support of a specialist. Since the neurological syndrome progresses slowly, follow-up care is always accompanied by active treatment of the symptoms. The patient is, after all, permanently in medical therapy and must accordingly take steps to process and relieve the associated stress.
Here’s what you can do yourself
As a rule, those affected by Anton’s syndrome cannot contribute directly to the therapy of the causal underlying disease. However, they can learn to cope with everyday life despite their disease, which, however, first requires that they accept it. The first step towards self-help and a great challenge for the patients and their relatives is the realization that there is indeed a visual disorder that needs to be treated. As long as the patients are unaware, it is important that the social environment confronts them with their suffering in a sensitive but consistent manner. For example, patients can be made aware of inconsistencies between visual and haptic perception. Thus, the patient can be asked to describe what another person is currently holding in his or her hand. The patient can then check for himself whether his visual perception matches what he is feeling. The use of ice cubes is particularly effective. Here, the affected person immediately recognizes that he sees something other than what he feels. The social environment must also ensure accident prevention. Furniture should not be moved, sharp-edged objects and tripping hazards such as carpets and runners should be removed, and access to stairwells should always be kept closed. Under no circumstances should the person affected still participate independently in road traffic. As long as the person is not aware of their blindness, they should not leave the house alone. In addition, efforts should be made to start psychotherapeutic or psychopharmacological therapy. As soon as the patient realizes that he or she is blind, attempts can be made to compensate for everyday deficits through physiotherapeutic measures.
